Electricity - Charges

1. The problem statement, all variables and given/known data
If an electroscope has a positive charge of 7.5 x 10[tex]^{-11}[/tex]C, how many electrons have been removed from the electroscope, if it was originally neutral?

(Answer: 4.7 x 10[tex]^{8}[/tex])

2. Relevant equations
I don't know :shy:

3. The attempt at a solution
Guys I seriously am clueless with this question. I understand basic electricity a little, like circuits, but I don't even know where to start with this. I have all formulas required, but I don't know which one to use, and my exam is tomorrow :uhh:

There are also some other questions which I'll probably post later, I'm really stuck on this, and your help is appreciated... a lot!

well... what you told me is like a completely new language to me... thanks for the help, but i really don't understand it (i understand what you're saying but i don't know what to do with that)... is there a specific equation i can use?

EDIT: I'm going to bed, my exam's early in the morning... I guess electricity won't be that great on the exam. Thanks everyone for the help.